Many types of medical implant devices are commonly utilized in modern medicine. Some of these devices can have drawbacks such as causing, allergic reaction or triggering blood clot formation. In implant devices such as stents, where the purpose of the device is to maintain an open artery or vein, the formation of a blood clot is contrary to the purpose of the device and can have negative effects which can even be life threatening.
Antithrombotic agents are of interest to utilize in conjunction with medical implant devices. Naturally occurring proteins that have antithrombotic or anticoagulation activity and can thereby alleviate blood clot formation include, for example, heparin. Heparin is known to act by binding to antithrombin III and inactivating thrombin. Recently, heparin has been utilized in conjunction with stents in attempt to prevent clot formation. However, heparin is mobile within the body and is able to diffuse away from the site of the stent. Accordingly, the effect of heparin under these circumstances is very short term. On the other hand, long term as well as short term effectiveness is desirable to deter clot formation and occlusion of the stent or blood vessel.
It is desirable to develop alternative implant devices and methods of forming implant devices to address these issues.